Wireless power transfer is becoming increasingly popular. Wireless power transfer involves transmitting power from a primary pad located on a stationary wireless power transfer device, such as a charging station, to a secondary pad on a mobile device, such as an electric vehicle, over a significant gap. The gap typically includes an air gap and can be significant. For example, the air gap may be from ground level to a secondary pad located under a vehicle. An air gap in the range of six inches to 10 inches is not uncommon. Prior to wireless power transfer, ensuring that the secondary pad is over the primary pad helps to provide a safe environment for wireless power transfer. Generating electromagnetic waves from the primary pad while the secondary pad is not in place over the primary pad can cause health risks, especially for people with pace makers, or other medical equipment that may be affected by the electromagnetic waves. Aligning a primary pad that transmits power with a secondary receiver pad can be difficult, especially when the secondary pad is under a vehicle.